Conventional Lucas reagent is a solution of zinc chloride in concentrated hydrochloric acid, and is made by reacting solid, anhydrous zinc chloride with 38% hydrochloric acid. One important utility for conventional Lucas reagent has been its use in reaction with menthol to form menthyl chloride, which in turn is used in the manufacture of neomenthyl diphenyl phosphine, a ligand useful in formulating catalysts used in the manufacture of certain non-steroidal antiinflammatory drugs.